Earth Berm — A mound of dirt next to exterior walls to provide wind protection and insulation.
Earth Cooling Tube — A long, underground metal or plastic pipe through which air is drawn. As air travels through the pipe it gives up some of its heat to the soil, and enters the house as cooler air.
Earth-Coupled Ground Source (Geothermal) Heat Pump — A type of heat pump that uses sealed horizontal or vertical pipes, buried in the ground, as heat exchangers through which a fluid is circulated to transfer heat.
Earth Sheltered Houses — Houses that have earth berms around exterior walls.
Earth-Ship — A registered trademark name for houses built with tires, aluminum cans, and earth.
Easement — An incorporated right, liberty, privilege, or use of another entity's property, distinct from ownership, without profit or compensation; a right-of-way.
Eccentric — A device for converting continuous circular motion into reciprocating rectilinear motion.
Economizer — A heat exchanger for recovering heat from flue gases for heating water or air.
Edge-Defined Film-Fed Growth (EFG) — A method for making sheets of polycrystalline silicon (for solar photovoltaic devices) in which molten silicon is drawn upward by capillary action through a mold.
Efficacy — The amount of energy service or useful energy delivered per unit of energy input. Often used in reference to lighting systems, where the visible light output of a luminary is relative to power input; expressed in lumens per Watt; the higher the efficacy value, the higher the energy efficiency.
Effective Capacity — The maximum load that a device is capable of carrying.
Efficiency — Under the First Law of Thermodynamics, efficiency is the ratio of work or energy output to work or energy input, and cannot exceed 100 percent. Efficiency under the Second Law of Thermodynamics is determined by the ratio of the theoretical minimum energy that is required to accomplish a task relative to the energy actually consumed to accomplish the task. Generally, the measured efficiency of a device, as defined by the First Law, will be higher than that defined by the Second Law.
Efficiency (Appliance) Ratings — A measure of the efficiency of an appliance's energy efficiency.
Elasticity of Demand — The ratio of the percentage change in the quantity of a good or service demanded to the percentage change in the price.
Electrical Energy - The energy of moving electrons.
Electrical Charge — A condition that results from an imbalance between the number of protons and the number of electrons in a substance.
Electrical System — All the conductors and electricity using devices that are connected to a source of electromotive force (or generator).
Electrical System Energy Losses — A measure of the amount of energy lost during the generation, transmission, and distribution of electricity.
Electric Circuit — The path followed by electrons from a generation source, through an electrical system, and returning to the source.
Electric Energy — The amount of work accomplished by electrical power, usually measured in kilowatt-hours (kWh). One kWh is 1,000 Watts and is equal to 3,413 Btu.
Electric Furnace — An air heater in which air is blown over electric resistance heating coils.
Electricity Generation — The process of producing electricity by transforming other forms or sources of energy into electrical energy; measured in kilowatt-hours.
Electricity Grid — A common term referring to an electricity transmission and distribution system.
Electric Rate — The unit price and quantity to which it applies as specified in a rate schedule or contract.
Electric Rate Schedule — A statement of the electric rate(s), terms, and conditions for electricity sale or supply.
Electric System — The physically connected generation, transmission, and distribution facilities and components operated as a unit.
Electric System Loss(es) — The total amount of electric energy loss in an electric system between the generation source and points of delivery.
Electric Power Plant — A facility or piece of equipment that produces electricity.
Electric Power Sector — Those privately or publicly owned establishments that generate, transmit, distribute, or sell electricity.
Electric Power Transmission — The transmission of electricity through power lines.
Electric Resistance Heating — A type of heating system where heat, resulting when electric current flows through an "element" or conductor, such as Nichrome, which has a high resistance, is radiated to a room.
Electric Utility - A corporation, person, agency, authority or other legal entity that owns and/or operates facilities for the generation, transmission, distribution or sale of electricity primarily for use by the public. Also known as a power provider.
Electric Vehicles — A battery-powered electrically driven vehicle.
Electricity Industry Restructuring — The process of changing the structure of the electric power industry from one of guaranteed monopoly over service territories, as established by the Public Utility Holding Company Act of 1935, to one of open competition between power suppliers for customers in any area.
Electrochemical Cell — A device containing two conducting electrodes, one positive and the other negative, made of dissimilar materials (usually metals) that are immersed in a chemical solution (electrolyte) that transmits positive ions from the negative to the positive electrode and thus forms an electrical charge. One or more cells constitute a battery.
Electrode — A conductor that is brought in conducting contact with a ground.
Electrodeposition — Electrolytic process in which a metal is deposited at the cathode from a solution of its ions.
Electrolysis — A chemical change in a substance that results from the passage of an electric current through an electrolyte. The production of commercial hydrogen by separating the elements of water, hydrogen, and oxygen, by charging the water with an electrical current.
Electrolyte — A nonmetallic (liquid or solid) conductor that carries current by the movement of ions (instead of electrons) with the liberation of matter at the electrodes of an electrochemical cell.
Electromagnetic Energy — Energy generated from an electromagnetic field produced by an electric current flowing through a superconducting wire kept at a specific low temperature.
Electromagnetic Field (EMF) — The electrical and magnetic fields created by the presence or flow of electricity in an electrical conductor or electricity consuming appliance or motor.
Electromotive Force — The amount of energy derived from an electrical source per unit quantity of electricity passing through the source.
Electron — An elementary particle of an atom with a negative electrical charge and a mass of 1/1837 of a proton; electrons surround the positively charged nucleus of an atom and determine the chemical properties of an atom.
Electronic Ballast — A device that uses electronic components to regulate the voltage of fluorescent lamps.
Electron Volt — The amount of kinetic energy gained by an electron when accelerated through an electric potential difference of 1 Volt; equivalent to 1.603 x 10^-12; a unit of energy or work; abbreviated as eV.
Electrostatic Precipitator — A device used to remove particulate matter from the waste gasses of a combustion power plant.
Ellipsoidal Reflector Lamp — A lamp where the light beam is focused 2 inches ahead of the lamp reducing the amount of light trapped in the fixture.
Emission(s) — A substance(s) or pollutant emitted as a result of a process.
Emission Factor — A measure of the average amount of a specified pollutant or material emitted for a specific type of fuel or process.
Emissivity — The ratio of the radiant energy (heat) leaving (being emitted by) a surface to that of a black body at the same temperature and with the same area; expressed as a number between 0 and 1.
Enclosure — The housing around a motor that supports the active parts and protects them. They come in different varieties (open, protected) depending on the degree of protection required.
Endothermic — A heat absorbing reaction or a reaction that requires heat.
End Use — The purpose for which useful energy or work is consumed.
Energize(d) — To send electricity through a electricity transmission and distribution network; a conductor or power line that is carrying current.
Energy — The capability of doing work; different forms of energy can be converted to other forms, but the total amount of energy remains the same.
Energy Audit — A survey that shows how much energy you use in your house or apartment. It will help you find ways to use less energy.
Energy Charge — That part of an electricity bill that is based on the amount of electrical energy consumed or supplied.
Energy Contribution Potential — Recombination occurring in the emitter region of a photovoltaic cell.
Energy Crops — Crops grown specifically for their fuel value. These include food crops such as corn and sugarcane, and nonfood crops such as poplar trees and switchgrass. Currently, two energy crops are under development: short-rotation woody crops, which are fast-growing hardwood trees harvested in 5 to 8 years; and herbaceous energy crops, such as perennial grasses, which are harvested annually after taking 2 to 3 years to reach full productivity.
Energy Efficient Mortgages — A type of home mortgage that takes into account the energy savings of a home that has cost-effective energy saving improvements that will reduce energy costs thereby allowing the homeowner to more income to the mortgage payment. A borrower can qualify for a larger loan amount than otherwise would be possible.
Energy Efficiency Ratio (EER) — The measure of the instantaneous energy efficiency of room air conditioners; the cooling capacity in Btu/hr divided by the watts of power consumed at a specific outdoor temperature (usually 95 degrees Fahrenheit).
Energy Density — The ratio of available energy per pound; usually used to compare storage batteries.
Energy Factor (EF) — The measure of overall efficiency for a variety of appliances. For water heaters, the energy factor is based on three factors: 1) the recovery efficiency, or how efficiently the heat from the energy source is transferred to the water; 2) stand-by losses, or the percentage of heat lost per hour from the stored water compared to the content of the water: and 3) cycling losses. For dishwashers, the energy factor is defined as the number of cycles per kWh of input power. For clothes washers, the energy factor is defined as the cubic foot capacity per kWh of input power per cycle. For clothes dryers, the energy factor is defined as the number of pounds of clothes dried per kWh of power consumed.
Energy End-Use Sectors — Major energy consuming sectors of the economy. The Commercial Sector includes commercial buildings and private companies. The Industrial Sector includes manufacturers and processors. The Residential Sector includes private homes. The Transportation Sector includes automobiles, trucks, rail, ships, and aircraft.
Energy Guide Labels — The labels placed on appliances to enable consumers to compare appliance energy efficiency and energy consumption under specified test conditions as required by the Federal Trade Commission.
Energy Intensity — The relative extent that energy is required for a process.
Energy Policy Act of 1992 (EPAct) — A comprehensive legislative package that mandates and encourages energy efficiency standards, alternative fuel use, and the development of renewable energy technologies. Public Law 102-486, October 24th, 1992. Also authorized the Federal Energy Regulatory Commission (FERC) to order the owners of electric power transmission lines to transmit or "wheel" power for power generators including electric power providers, federal power marketing authorities, and exempt wholesale generators.
Energy Security Act of 1980 — Legislation authorizing a U.S. biomass and alcohol fuel program, and that authorized loan guarantees and price guarantees and purchase agreements for alcohol fuel production.
Energy Service Company (ESCO) — A company that specializes in undertaking energy efficiency measures under a contractual arrangement whereby the ESCO shares the value of energy savings with their customer.
Energy Storage — The process of storing, or converting energy from one form to another, for later use; storage devices and systems include batteries, conventional and pumped storage hydroelectric, flywheels, compressed gas, and thermal mass.
Enthalpy — A thermodynamic property of a substance, defined as the sum of its internal energy plus the pressure of the substance times its volume, divided by the mechanical equivalent of heat. The total heat content of air; the sum of the enthalpies of dry air and water vapor, per unit weight of dry air; measured in Btu per pound (or calories per kilogram).
Entrained Bed Gasifier — A gasifier in which the feedstock (fuel) is suspended by the movement of gas to move it through the gasifier.
Entropy — A measure of the unavailable or unusable energy in a system; energy that cannot be converted to another form.
Environment — All the natural and living things around us. The earth, air, weather, plants, and animals all make up our environment.
Epitaxial Growth — In reference to solar photovoltaic devices, the growth of one crystal on the surface of another crystal. The growth of the deposited crystal is oriented by the lattice structure of the original crystal.
Equinox — The two times of the year when the sun crosses the equator and night and day are of equal length; usually occurs on March 21st (spring equinox) and September 23 (fall equinox).
Erg — A unit of work done by the force of one dyne acting through a distance of one centimeter.
Ethanol — Ethyl alcohol (C2H5OH) — A colorless liquid that is the product of fermentation used in alcoholic beverages, industrial processes, and as a fuel additive. Also known as grain alcohol.
Ethyl Tertiary Butyl Ether (ETBE) — A chemical compound produced in a reaction between ethanol and isobutylene (a petroleum-derived by-product of the refining process). ETBE has characteristics superior to other ethers: low volatility, low water solubility, high octane value, and a large reduction in carbon monoxide and hydrocarbon emissions.
Eutectic — A mixture of substances that has a melting point lower than that of any mixture of the same substances in other proportions.
Eutectic Salts — Salt mixtures with potential applications as solar thermal energy storage materials.
Evacuated-Tube Collector — A collector is the mechanism in which fluid (water or diluted antifreeze, for example) is heated by the sun in a solar hot water system. Evacuated-tube collectors are made up of rows of parallel, transparent glass tubes. Each tube consists of a glass outer tube and an inner tube, or absorber. The absorber is covered with a selective coating that absorbs solar energy well but inhibits radiative heat loss. The air is withdrawn ("evacuated") from the space between the tubes to form a vacuum, which eliminates conductive and convective heat loss. Evacuated-tube collectors are used for active solar hot water systems.
Evaporation — The conversion of a liquid to a vapor (gas), usually by means of heat.
Evaporative Cooling — The physical process by which a liquid or solid is transformed into the gaseous state. For this process a mechanical device uses the outside air's heat to evaporate water that is held by pads inside the cooler. The heat is drawn out of the air through this process and the cooled air is blown into the home by the cooler's fan.
Evaporator Coil — The inner coil in a heat pump that, during the cooling mode, absorbs heat from the inside air and boils the liquid refrigerant to a vapor, which cools the house.
Excitation — The power required to energize the magnetic field of a generator.
Exempt Wholesale Generator — An unregulated subsidiary of a power provider that is allowed to generate and sell wholesale power as an independent energy producer, and is exempt from the Public Utility Holding Company Act of 1935.
Exothermic — A reaction or process that produces heat; a combustion reaction.
Expanded Polystyrene — A type of insulation that is molded or expanded to produce coarse, closed cells containing air. The rigid cellular structure provides thermal and acoustical insulation, strength with low weight, and coverage with few heat loss paths. Often used to insulate the interior of masonry basement walls.
Expansion Tank — A tank used in a closed-loop solar heating system that provides space for the expansion of the heat transfer fluid in the pressurized collector loop.
Expansion Valve — The device that reduces the pressure of liquid refrigerant thereby cooling it before it enters the evaporator coil in a heat pump.
External Combustion Engine — An engine in which fuel is burned (or heat is applied) to the outside of a cylinder; a Stirling engine.
Externality — The environmental, social, and economic impacts of producing a good or service that are not directly reflected in the market price of the good or service.
Extruded Polystyrene — A type of insulation material with fine, closed cells, containing a mixture of air and refrigerant gas. This insulation has a high R-value, good moisture resistance, and high structural strength compared to other rigid insulation materials.
Fan — A device that moves and/or circulates air and provides ventilation for a room or a building.
Fan Coil — A heat exchanger coil in which a fluid such as water is circulated and a fan blows air over the coil to distribute heat or cool air to the different rooms.
Fan Velocity Pressure — The pressure corresponding to the outlet velocity of a fan; the kinetic energy per unit volume of flowing air.
Farad — A unit of electrical capacitance; the capacitance of a capacitor between the plates of which there appears a difference of 1 Volt when it is charged by one coulomb of electricity.
Feather — In a wind energy conversion system, to pitch the turbine blades so as to reduce their lift capacity as a method of shutting down the turbine during high wind speeds.
Federal Energy Management Program (FEMP) — A program of the U.S. Department of Energy (DOE) that implements energy legislation and presidential directives. FEMP provides project financing, technical guidance and assistance, coordination and reporting, and new initiatives for the federal government. It also helps federal agencies identify the best technologies and technology demonstrations for their use.
Federal Energy Regulatory Commission (FERC) — This is an independent regulatory agency within the U.S. DOE that has jurisdiction over interstate electricity sales, wholesale electric rates, natural gas pricing, oil pipeline rates, and gas pipeline certification. It also licenses and inspects private, municipal, and state hydroelectric projects and oversees related environmental matters.
Federal Power Marketing Administrations (PMA) — These are separate and distinct organizational agencies within the U.S. DOE that market power at federal multipurpose water projects at lowest possible rates to consumers consistent with sound business principles. There are five PMA's: Alaska Power Administration, Bonneville Power Administration, Southeastern Power Administration, Southwestern Power Administration, Western Area Power Administration.
Feeder — A power line for supplying electricity within a specified area.
Feedstock — A raw material that can be converted to one or more products.
Fenestration — The arrangement, proportion, and design of windows in a building.
Fermentation — The decomposition of organic material to alcohol, methane, etc., by organisms, such as yeast or bacteria, usually in the absence of oxygen.
Fiberglass Insulation — A type of insulation, composed of small diameter pink, yellow, or white glass fibers, formed into blankets or batts, or used in loose-fill and blown-in applications.
Filament — A coil of tungsten wire suspended in a vacuum or inert gas-filled bulb. When heated by electricity the tungsten "filament" glows.
Fill Factor — The ratio of a photovoltaic cell's actual power to its power if both current and voltage were at their maxima. A key characteristic in evaluating cell performance.
Filter (air) — A device that removes contaminants, by mechanical filtration, from the fresh air stream before the air enters the living space. Filters can be installed as part of a heating/cooling system through which air flows for the purpose of removing particulates before or after the air enters the mechanical components.
Fin — A thin sheet of material (metal) of a heat exchanger that conducts heat to a fluid.
Finish — Both a noun and a verb to describe the exterior surface of building elements (walls, floors, ceilings, etc.) and furniture, and the process of applying it.
Fire Classification — Classifications of fires developed by the National Fire Protection Association.
Fireplace — A wood or gas burning appliance that is primarily used to provide ambiance to a room. Conventional, masonry fireplaces without energy saving features, often take more heat from a space than they put into it.
Fireplace Insert — A wood or gas burning heating appliance that fits into the opening or protrudes on to the hearth of a conventional fireplace.
Fire-Rating - The ability of a building construction assembly (partition, wall, floor, etc.) to resist the passage of fire. The rating is expressed in hours.
Firewall — A wall to prevent the spread of fire; usually made of non-combustible material.
Firing Rate — The amount of BTUs/hour or kWs produced by a heating system from the burning of a fuel.
First Law of Thermodynamics — States that energy cannot be created or destroyed, but only changed from one form to another. First Law efficiency measures the fraction of energy supplied to a device or process that it delivers in its output. Also called the law of conservation of energy.
Fiscal Year (FY) — The U.S. Government's 12-month financial year, from October to September, of the following calender year; e.g.: FY 1998 extends from Oct. 1, 1997 to Sept. 30, 1988.
Flame Spread Classification — A measure of the surface burning characteristics of a material.
Flame Spread Rating — A measure of the relative flame spread, and smoke development, from a material being tested. The flame spread rating is a single number comparing the flame spread of a material with red oak, arbitrarily given the number 100 and asbestos cement board with a flame spread of 0. Building codes require a maximum flame spread of 25 for insulation installed in exposed locations.
Flash-Steam Geothermal Plants — When the temperature of the hydrothermal liquids is over 350 F (177 C), flash-steam technology is generally employed. In these systems, most of the liquid is flashed to steam. The steam is separated from the remaining liquid and used to drive a turbine generator. While the water is returned to the geothermal reservoir, the economics of most hydrothermal flash plants are improved by using a dual-flash cycle, which separates the steam at two different pressures. The dual-flash cycle produces 20% to 30% more power than a single-flash system at the same fluid flow.
Flashing — Metal, usually galvanized sheet metal, used to provide protection against infiltration of precipitation into a roof or exterior wall; usually placed around roof penetrations such as chimneys.
Flashpoint — The minimum temperature at which sufficient vapor is released by a liquid or solid (fuel) to form a flammable vapor-air mixture at atmospheric pressure.
Flat-Black Paint — Nonglossy paint with a relatively high absorptance.
Flat Plate Solar Thermal/Heating Collectors — Large, flat boxes with glass covers and dark-colored metal plates inside that absorb and transfer solar energy to a heat transfer fluid. This is the most common type of collector used in solar hot water systems for homes or small businesses.
Flat Plate Solar Photovoltaic Module — An arrangement of photovoltaic cells or material mounted on a rigid flat surface with the cells exposed freely to incoming sunlight.
Flat Roof — A slightly sloped roof, usually with a tar and gravel cover. Most commercial buildings use this kind of roof.
Float-Zone Process — In reference to solar photovoltaic cell manufacture, a method of growing a large-size, high-quality crystal whereby coils heat a polycrystalline ingot placed atop a single-crystal seed. As the coils are slowly raised the molten interface beneath the coils becomes a single crystal.
Floor — The upward facing structure of a building.
Floor Space — The interior area of a building, calculated in square feet or meters.
Flow Condition — In reference to solar thermal collectors, the condition where the heat transfer fluid is flowing through the collector loop under normal operating conditions.
Flow Restrictor — A water and energy conserving device that limits the amount of water that a faucet or shower head can deliver.
Flue — The structure (in a residential heating appliance, industrial furnace, or power plant) into which combustion gases flow and are contained until they are emitted to the atmosphere.
Flue Gas — The gas resulting from the combustion of a fuel that is emitted to the flue.
Fluffing — The practice of installing blow-in, loose-fill insulation at a lower density than is recommended to meet a specified R-Value.
Fluidized Bed Combustion (FBC) — A type of furnace or reactor in which fuel particles are combusted while suspended in a stream of hot gas.
Fluorescent Light — The conversion of electric power to visible light by using an electric charge to excite gaseous atoms in a glass tube. These atoms emit ultraviolet radiation that is absorbed by a phosphor coating on the walls of the lamp tube. The phosphor coating produces visible light.
Fly Ash — The fine particulate matter entrained in the flue gases of a combustion power plant.
Flywheel Effect — The damping of interior temperature fluctuations by massive construction.
Foam (Insulation) — A high R-value insulation product usually made from urethane that can be injected into wall cavities, or sprayed onto roofs or floors, where it expands and sets quickly.
Foam Board — A plastic foam insulation product, pressed or extruded into board-like forms, used as sheathing and insulation for interior basement or crawl space walls or beneath a basement slab; can also be used for exterior applications inside or outside foundations, crawl spaces, and slab-on-grade foundation walls.
Foam Core Panels — A type of structural, insulated product with foam insulation contained between two facings of drywall, or structural wood composition boards such as plywood, waferboard, and oriented strand board.
Foot Candle — A unit of illuminance; equal to one lumen per square foot.
Foot Pound — The amount of work done in raising one pound one foot.
Force — The push or pull that alters the motion of a moving body or moves a stationary body; the unit of force is the dyne or poundal; force is equal to mass time velocity divided by time.
Forced Air System or Furnace — A type of heating system in which heated air is blown by a fan through air channels or ducts to rooms.
Forced Ventilation — A type of building ventilation system that uses fans or blowers to provide fresh air to rooms when the forces of air pressure and gravity are not enough to circulate air through a building.
Formaldehyde — A chemical used as a preservative and in bonding agents. It is found in household products such as plywood, furniture, carpets, and some types of foam insulation. It is also a by-product of combustion and is a strong-smelling, colorless gas that is an eye irritant and can cause sneezing, coughing, and other health problems.
Fossil Fuels - Fuels formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels. Oil, natural gas, and coal are fossil fuels.
Foundation — The supportive structure of a building.
Fractional Horse Power Motor — An electric motor rated at less than one horse power (hp).
Frame (Window) — The outer casing of a window that sits in a designated opening of a structure and holds the window panes in place.
Framing — The structural materials and elements used to construct a wall.
Francis Turbine — A type of hydropower turbine that contains a runner that has water passages through it formed by curved vanes or blades. As the water passes through the runner and over the curved surfaces, it causes rotation of the runner. The rotational motion is transmitted by a shaft to a generator.
Frequency — The number of cycles through which an alternating current passes per second; in the U.S. the standard for electricity generation is 60 cycles per second (60 Hertz).
Freon — A registered trademark for a cholorfluorocarbon (CFC) gas that is highly stable and that has been historically used as a refrigerant.
Fresnel Lens — An optical device for concentrating light that is made of concentric rings that are faced at different angles so that light falling on any ring is focused to the same point.
Friction Head — The energy lost from the movement of a fluid in a conduit (pipe) due to the disturbances created by the contact of the moving fluid with the surfaces of the conduit, or the additional pressure that a pump must provide to overcome the resistance to fluid flow created by or in a conduit.
Fuel — Any material that can be burned to make energy.
Fuel Cell — An electrochemical device that converts chemical energy directly into electricity.
Fuel Efficiency — The ratio of heat produced by a fuel for doing work to the available heat in the fuel.
Fuel Grade Alcohol — Usually refers to ethanol to 160 to 200 proof.
Fuel Oil — Any liquid petroleum product burned for the generation of heat in a furnace or firebox, or for the generation of power in an engine. Domestic (residential) heating fuels are classed as Nos. 1, 2, 3; Industrial fuels as Nos. 4, 5, and 6.
Fuel Rate — The amount of fuel necessary to generate one kilowatt-hour of electricity.
Full Sun — The amount of power density in sunlight received at the earth's surface at noon on a clear day (about 1,000 Watts/square meter).
Fungi — Plant-like organisms with cells with distinct nuclei surrounded by nuclear membranes, incapable of photosynthesis. Fungi are decomposers of waste organisms and exist as yeast, mold, or mildew.
Furling — The process of forcing, either manually or automatically, a wind turbine's blades out of the direction of the wind in order to stop the blades from turning.
Furnace (Residential) — A combustion heating appliance in which heat is captured from the burning of a fuel for distribution, comprised mainly of a combustion chamber and heat exchanger.
Fuse — A safety device consisting of a short length of relatively fine wire, mounted in a holder or contained in a cartridge and connected as part of an electrical circuit. If the circuit source current exceeds a predetermined value, the fuse wire melts (i.e. the fuse 'blows') breaking the circuit and preventing damage to the circuit protected by the fuse.
Air Conditioning Units
